This invention relates to sawing apparatus and particularly to a sawing apparatus adaptable to receive cants of varying thickness.
In a conventional sawmill, a generally cylindrical log is cut substantially longitudinally to form flitches, each flitch having two parallel main faces and one or two wane edges. The flitch is sawn to remove the wane edge(s), and the resulting cant is delivered longitudinally to a gang edger for cutting into boards or strips.
A conventional gang edger comprises plural bed rolls that define a horizontal bed plane and multiple circular saws mounted on a common horizontal arbor positioned below the bed plane. Saw guides of durable low friction material, such as Babbitt metal, are provided between each two adjacent saws, just below the bed plane. A cant that is to be edged is fed through the edger on the bed rolls so that the surface of the cant toward the teeth entering the cant is close to the saw guides and the saw guides limit wandering of the saws as the cant is fed through the edger. This type of edger provides high accuracy in sawing, but has a disadvantage in that the cutting teeth pass upwardly through the cant, causing sawdust to be thrown upwardly. Efficient collection of this sawdust material is difficult.
The foregoing disadvantage may be avoided if the saw arbor were placed above the cant, whereby the sawdust is thrown downwardly and collected beneath the bed plane of the edger. However, this construction has not hitherto been practical because cants are usually not all the same thickness. For example, an edger might have to handle cants having a minimum nominal thickness of four inches up to a maximum nominal thickness of ten inches in approximately two inch increments. If the arbor were positioned to allow ten inch cants to be cut, a four inch cant would be approximately six inches from the saw guides, and accordingly the sawing accuracy of the edger would be seriously impaired.